Can You Differentiate a Bad Fuel Pump vs Bad Fuel Filter?


Are you noticing that your vehicle is spending more fuel than it is used to? Perhaps your vehicle is also experiencing a reduction in engine power? In many situations, your vehicle could be suffering from a bad fuel pump or a bad fuel filter. However, it is important to know which part of your vehicle is the culprit. Here, we will take a look at how you can differentiate between a bad fuel pump and a bad fuel filter. 

What is a fuel pump? 

A fuel pump is a component that transfers gas from the fuel tank to the carburetor or fuel injector to the engine. Typically, a fuel pump will have a lifespan of about 100,000 miles.

What is a fuel filter? 

A filter in the fuel line removes dirt or rust from the fuel before it reaches the engine. The fuel filter is a cartridge that contains several layers of paper. For fuel to remain clean, the fuel filter needs to be replaced every 20,000 to 30,000 miles. 

How to tell if your fuel pump is bad

If your vehicle has a bad fuel pump, then it could be suffering from one of several conditions. Here’s a look at some of the main issues that are caused by a bad fuel pump.

1). Sputtering engine

If you are trying to travel at a high speed and you notice that your engine is sputtering it is because the fuel pump is not able to deliver enough gas to meet the increasing demands of the engine. 

2). Overheating engine

At the end of its lifecycle, a failing fuel pump will cause the engine to overheat. Now, you may think that only the radiator could cause an overheated engine. However, your engine can overheat and stall out when the fuel pump is failing. 

3). Low fuel pressure

Naturally, a failing fuel pump will deliver lower than usual fuel pressure. If you want to measure the fuel pressure on your vehicle, you can purchase a fuel pressure gauge and have a friend check the reading while you rev the engine. A low reading will be a good indicator that you have a fuel pump issue. 

4). Surging engine

There are times when a fuel pump can fail by sending too much fuel to the engine. This can cause your vehicle to unexpectedly surge ahead. This is a potentially dangerous issue that needs to be resolved right away. 

5). Decreasing mileage 

Also, you can experience decreasing fuel mileage because the relief valve on the fuel pump is not operating properly. This will cause more than usual gas to flow into the engine. Thus, you will be spending more gas and decreasing your overall fuel mileage. 

5). Dead engine

Finally, if your fuel pump fails, then it will not be able to send any fuel to the engine. This will essentially leave you on the side of the road. At this time, you will need to replace your fuel pump. 

How to tell if your fuel filter is bad

If you have a bad fuel filter, your vehicle may suffer from some similar issues experienced by a bad fuel pump. However, there are some differences. Here’s a look at some symptoms of a bad fuel pump. 

1). Difficulty starting your car

One of the first signs that your fuel filter is going bad is that you are having difficulty starting your car. That’s because a clogged fuel filter will restrict the flow of gas to the engine. 

2). Burning more fuel 

When your fuel filter is clogged, you will naturally have a less efficient engine. This will lead to you using more fuel to run your vehicle. 

3). Car jerks when going uphill 

When you are driving your car uphill, it will need more power. However, that extra power will not be responsive with a clogged fuel filter. Therefore, you will experience jerking while your car is trying to make its way uphill.

4). Reduced engine power 

Naturally, your vehicle will experience an over-reduction in power with a clogged fuel filter. This will be most apparent if you are trying to accelerate from a complete stop or pass another vehicle on the highway. 

5). Fuel pump failure

At a certain point, a clogged fuel filter will cause your fuel pump to fail. When this happens, you will have to replace the fuel filter as well as the fuel pump. 

6). Engine stalls while idling 

If you notice that your engine is stalling while it is idling, then the cause could be a clogged fuel filter. This is because there is not an adequate amount of fuel making its way to the engine. 

Common Issues of a bad fuel pump and a bad fuel filter 

Two of the common issues between both a bad fuel pump and a bad fuel filter is that you will experience increased fuel consumption and less power. In short, your vehicle’s engine will be less efficient. This makes sense since any issue with your fuel will lead to a reduction in overall performance. 

How to differentiate between a bad fuel pump and a bad fuel filter 

We talked about some of the common issues that you can face when either your fuel pump or fuel filter is bad. However, let’s take a look at some of the unique issues of a bad fuel pump and a bad fuel filter:

If your vehicle is getting too much fuel into the engine, it is a fuel pump issue

A bad fuel filter can restrict the amount of gas that comes into your engine. However, a bad fuel pump can either restrict or cause too much fuel to go onto your engine. Therefore, if more than the usual amount of fuel is going into your engine, then it is a fuel pump issue. 

If your car is dead, it is a fuel pump issue

It is highly unlikely that a bad fuel filter will completely restrict fuel from getting to your engine. However, a bad fuel pump can completely cut off your vehicle’s ability to send any fuel to the engine. This will lead to a “dead car.” 

If your vehicle overheats, then it is a fuel pump issue 

If you notice that your engine is overheating, then this will be unique to the fuel pump. A bad fuel filter will typically not lead to engine overheating. 

Which is the more serious issue? 

While both the fuel filter and the fuel pump are part of the fuel system, the fuel pump is the more critical component of the vehicle. Therefore, if you have a fuel pump issue, it will cost more in parts and labor to address. A fuel filter is a more minor issue that can be addressed with a quick filter change. 

However, it should be noted that both the fuel filter and the fuel pump are both important parts of your vehicle and they should be maintained at their regularly scheduled times. 

  • Fuel filter – Replace every 15,000 to 30,000 miles
  • Fuel pump – Replace every 100,000 miles 

The cost of replacing a fuel filter

You will need to have your fuel filter replaced more often than your fuel pump. Therefore, you will not have to pay as much. Also, replacing the fuel filter is quicker. Here’s a look at how much it will typically cost to replace a fuel filter on your average vehicle. 

Service center

The typical price to replace the fuel filter at a service center is going to range between $100 and $200 when you add in the cost of parts and labor. The service time is usually under an hour. 

DIY 

If you typically work on your vehicle, then you can find a fuel filter at your local auto parts store for between $10 and $30. Even if you are not the most experienced shade tree mechanic, you should be able to complete the job yourself. 

The cost of replacing a fuel pump 

You may only need to have your vehicle’s fuel pump replaced once during the time that you own your car. Therefore, it is more of a major service compared to replacing the fuel filter. Here’s a look at how much replacing a fuel pump costs at a service center versus doing it yourself. 

Service center

The average cost of a fuel pump will vary widely depending on the type of fuel pump (non-electric vs electric) and the type of vehicle. The price range on a fuel pump, including parts and service, will range from $220 to $1,000. 

DIY 

You can also purchase a fuel pump at your local auto parts store. The price will range by the type of fuel pump. A non-electric fuel pump will cost anywhere from $20 to $40 while an electric fuel pump will cost anywhere from $50 to $200. 

Understanding the difference between a bad fuel pump and a bad fuel filter 

Whenever there is an issue with your vehicle, it is important to know exactly what is going on. This will allow you to quickly resolve the issue without having to replace more than one part or system on your vehicle. If you are unsure about how to diagnose the issue yourself, then be sure to take your vehicle to a trusted service center for service. 

REFERENCE:

https://blog.protectmycar.com/bad-fuel-filter

https://www.primarycareauto.com/7-signs-your-fuel-pump-is-going-out/

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